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Great Blue Heron

The statuesque form and elegant plumage of the Great Blue Heron make this one of nature's finest achievements. It is not surprising that its Asian relatives have figured prominently in Chinese and Japanese art for centuries. While the sight of the Great Blue Heron in motionless contemplation of a potential meal or sailing majestically across a vast salt marsh is always a rare treat, the species is presently becoming more common in New England.

NATURAL HISTORY
The Great Blue Heron is widespread in North America. It nests from southeastern Alaska and central Canada, south through Florida and Mexico. It winters over much of its breeding range, which extends as far south as the West Indies and the Galapagos Islands.

Migrating Great Blue Herons arrive in New England as early as the latter part of March, and migrate southward between mid-July and late September. Some birds winter over and are found in coastal areas or where freshwater remains open.

Great Blue Herons have dramatically increased in Massachusetts in recent years. According to a 1996 survey conducted by the Massachusetts Division of Fisheries and Wildlife, there were over 700 active nests at 63 sites throughout the state.

IDENTIFICATION
The Great Blue Heron is unmistakable. Its color and pattern are unique, and in New England, only the pure white Great Egret approaches its four foot height. Herons are often mistakenly called cranes, and the Great Blue superficially resembles the Sandhill Crane, which nested in Massachusetts up until the early colonial period.

NESTING
Though solitary while feeding and during the nonbreeding season, Great Blues nest primarily in colonies, called rookeries, containing up to fifty pair.

In Massachusetts, beaver swamps are the predominant breeding grounds. The heron's nest is built high in the timbers of drowned, dead trees, or more rarely in live deciduous or evergreen trees. Because of the increase in New England beaver populations within the last thirty years, much additional nesting habitat has recently been created. Here Great Blues nest only with their own species and not in mixed colonies with other species of wading birds. Herons typically use the same rookery every year. The nests are flat platforms made of sticks and lined with moss, pine needles, and other leaf material. The nests are added to each year, eventually becoming very bulky and measuring up to four feet in diameter.

YOUNG
Usually four eggs are laid, and, after about twenty-eight days, the hatchlings emerge. At first, the young are nearly helpless, and both parents are kept busy supplying them with regurgitated food. Eventually, small fish are simply deposited in the nest for the chicks to pick up.

Young herons are able to fly in about sixty days. In about ninety days, they become independent and disperse throughout New England and beyond. The young do not breed until they are at least two years old. In a typical brood, only two young survive. Nestling and fledgling mortality is attributed to a number of causes including starvation, falling out of a nest, predators (such as raccoons and foxes), and disturbance by people in the rookeries.

FOOD
Great Blue Herons feed mainly on fish, but their diet also includes, crabs, insects, frogs, snakes, salmanders, grasshoppers, dragonflies, aquatic insects, and, occasionally, small rodents.

HERON CONSERVATION
Human creations such as power lines, toxic waste, pesticides, and discarded plastic six-pack rings and monofilament fish line continue to pose a threat to the survival of herons. Also, rookeries are sensitive to human disturbances and land development pressures, making local conservation of wetland habitat crucial for long-term survival of these magnificent birds.

SITUATIONS AND SOLUTIONS

Conflicts between people and Great Blue Herons occasionally arise when a heron feeds in a fishpond stocked with exotic and most likely, expensive fish. To the heron it's just another pond with fish - a food source.

SOLUTION
Using loud noises and perseverance, continuously scare the bird off. After a while it should become discouraged and look elsewhere for food.

Place several 18-inch-high stakes around the pond. Using 3-inch-wide, silver mylar tape (found with the crepe paper in party-supply stores) crisscross the pond a number of times, securing the tape to the stakes. Before securing it, twist the mylar tape a few times and leave some slack so it moves in the breeze and reflects the light.

HERONS AND THE LAW
Great Blue Herons are protected by the Federal Migratory Bird Treaty Act of 1918. It is illegal to capture, possess, or cause harm to a Great Blue Heron or its nest or eggs.

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